Microleakage in Ceramic Inlays Luted with Different Resin Cements

The objective of this in vitro study was to evaluate the microleakage in ceramic inlays using different resin cements with margins in enamel and cementum/dentin interfaces. Standard Class II MOD inlay cavities were prepared in 32 noncarious human premolars. The cavities were randomly divided into 4 groups (n = 8): Control group: cavities were treated with Single Bond and incrementally filled with a composite resin (P60); Enforce group: feldspathic ceramic inlays were luted using Prime & Bond 2.1 and Enforce; RelyX group: inlays were cemented with Single Bond and RelyX ARC; Resin Cement group: ceramic inlays were bonded using Single Bond and Resin Cement. Ceramic inlays were previously treated with 10% hydrofluoric acid for 2 min, followed by silane application. After 7 days of storage in distilled water, teeth were submitted to thermocycling. After applying nail varnish, specimens were immersed in 2% aqueous solution of methylene blue for 8 h. After washing, teeth were cut into three sections through the restorations, and the leakage was assessed using a standardized score. Data were submitted to statistical analysis using nonparametric tests (Mann-Whitney and Kruskal-Wallis). Dye leakage at margins in enamel was statistically lower (p 0.01) than at cementum/dentin interfaces. RelyX ARC performed better (p 0.05) than resin cement (enamel) and composite restorations (cementum/dentin). No other statistical differences were observed. Both the material and the substrate interface influenced microleakage of the ceramic inlays.